Worksheet

The Sun's life from start to finish

Grade 9 Science Worksheet - Building Confidence

NameDate

Circle the best answer.

  1. Timeline ruler of the Sun's life with a dot at now. The Sun is now fusing hydrogen into helium in its core. Which stage of life is it in, by Ari's reading?

    • White dwarf
    • Protostar
    • Main sequence
    • Red giant

  2. The Sun's last stage is a hot core about the size of Earth that slowly cools. What is it called, by Kira's reading?

    • A black hole
    • A neutron star left by a supernova
    • White dwarf
    • A small star still fusing hydrogen

  3. Which order matches the Sun's life from start to finish, by Jun's reading?

    • Protostar → red giant → main sequence → white dwarf
    • Nebula → main sequence → white dwarf → red giant
    • Nebula → protostar → main sequence → red giant → white dwarf
    • Nebula → protostar → main sequence → supernova

  4. What comes right after the main sequence for the Sun, by Luz's reading?

    • It shrinks straight to a white dwarf
    • It goes dark at once
    • It swells into a red giant
    • It explodes as a supernova

  5. What happens right before the Sun becomes a white dwarf, by Milo's reading?

    • A protostar forms
    • A supernova blast
    • Its outer layers drift away as a planetary nebula
    • The main sequence begins

  6. On the timeline, about how long ago did the Sun form, by Noah's reading (NASA)?

    • About 4.6 million years ago
    • About 4,600 years ago
    • About 10 billion years ago
    • About 4.6 billion years ago

  7. About how much main-sequence time does the Sun have left, by Ren's reading?

    • About 5 billion years
    • It ends within the next century
    • About 10 billion years more
    • About 50 years

  8. Star card cutaway of a red giant with its core marked. What does the core of a red giant like the future Sun fuse, by Tala's reading (NASA)?

    • Nothing; fusion has stopped for good
    • Hydrogen into helium, just as now
    • Iron into gold
    • Helium into carbon

  9. Why does a white dwarf glow, by Zee's reading (NASA)?

    • It reflects light from other stars
    • It fuses hydrogen like the Sun today
    • It is still hot and slowly cools; no fusion happens
    • It fuses helium in its core

  10. About how big is a white dwarf, by Esme's reading (NASA)?

    • Hundreds of times the Sun's size
    • About 20 km across, like a neutron star
    • The same size as the Sun now
    • Roughly the size of Earth
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The Sun's life from start to finish

Answer Key - Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

  1. Timeline ruler of the Sun's life with a dot at now. The Sun is now fusing hydrogen into helium in its core. Which stage of life is it in, by Ari's reading?

    • White dwarf
    • Protostar
    • Main sequence
    • Red giant

  2. The Sun's last stage is a hot core about the size of Earth that slowly cools. What is it called, by Kira's reading?

    • A black hole
    • A neutron star left by a supernova
    • White dwarf
    • A small star still fusing hydrogen

  3. Which order matches the Sun's life from start to finish, by Jun's reading?

    • Protostar → red giant → main sequence → white dwarf
    • Nebula → main sequence → white dwarf → red giant
    • Nebula → protostar → main sequence → red giant → white dwarf
    • Nebula → protostar → main sequence → supernova

  4. What comes right after the main sequence for the Sun, by Luz's reading?

    • It shrinks straight to a white dwarf
    • It goes dark at once
    • It swells into a red giant
    • It explodes as a supernova

  5. What happens right before the Sun becomes a white dwarf, by Milo's reading?

    • A protostar forms
    • A supernova blast
    • Its outer layers drift away as a planetary nebula
    • The main sequence begins

  6. On the timeline, about how long ago did the Sun form, by Noah's reading (NASA)?

    • About 4.6 million years ago
    • About 4,600 years ago
    • About 10 billion years ago
    • About 4.6 billion years ago

  7. About how much main-sequence time does the Sun have left, by Ren's reading?

    • About 5 billion years
    • It ends within the next century
    • About 10 billion years more
    • About 50 years

  8. Star card cutaway of a red giant with its core marked. What does the core of a red giant like the future Sun fuse, by Tala's reading (NASA)?

    • Nothing; fusion has stopped for good
    • Hydrogen into helium, just as now
    • Iron into gold
    • Helium into carbon

  9. Why does a white dwarf glow, by Zee's reading (NASA)?

    • It reflects light from other stars
    • It fuses hydrogen like the Sun today
    • It is still hot and slowly cools; no fusion happens
    • It fuses helium in its core

  10. About how big is a white dwarf, by Esme's reading (NASA)?

    • Hundreds of times the Sun's size
    • About 20 km across, like a neutron star
    • The same size as the Sun now
    • Roughly the size of Earth